A ban on plastic bags has come into force in Kenya and those found violating the new regulation could be receive maximum fines of 38,000 US dollars (£30,000) or a four-year jail term.

The ban applies to the use, manufacture, and importation of plastic shopping bags and gives a minimum fine of about 19,000 US dollars (£14,700) or up to a year imprisonment, according to Kenyan government.

Exemptions were made for those producing plastic bags for industrial purposes.

The Kenyan government says the bags harm the environment, block sewers and don't decompose.

Some 100 million plastic bags are handed out every year in Kenya by supermarkets alone, according to the UN Environment Programme.

Similar bans have been implemented in other African countries such as Cameroon, Guinea-Bissau, Mali, Tanzania, Uganda, Ethiopia, Mauritania and Malawi.

Some Kenyan manufacturers have said the ban will cost jobs but Environment Minister Judi Wakhungu last week said more jobs will be created from making bags from environment-friendly materials.

The plastic bags have long been identified as a major cause of environmental damage and health problems, killing birds, fish and other animals that mistake them for food, said the UN environment agency.

The bags also damage agricultural land, pollute tourist sites and provide breeding grounds for the mosquitoes that carry malaria and dengue fever.

Plastic bags contribute to the eight million tons of plastic carried into the ocean every year.

At current rates by 2050 there will be more plastic in the oceans than fish, according to the UN agency.